CL PIX: Barca draw at Milan; Dortmund spoil Wenger's birthday

Lionel Messi slipped past tight AC Milan marking to score in his first start since injury and give Barcelona a 1-1 draw on Tuesday that keeps them two points clear at the top of Champions League Group H.

The Argentine struck in the 23rd minute with a slick finish to a breakaway move to cancel out Robinho's stylish ninth minute opener, which came during a frantic opening period of pressure from the home side.

Barcelona moved up to seven points, with unbeaten Milan in second spot on five, two ahead of Celtic who beat Ajax 2-1 in Glasgow.

However, coach Gerardo Martino was less than happy with a point from a match he felt Barca should have won.

"I think with the way the match went we dropped two points tonight. A point isn't any good for us and we deserved more. We created chances and deserved to win," Argentine Martino told Sky Sport Italia.

"It didn't work for the first ten minutes of the match, we gave Milan the initiative. We didn't play like we did for the remaining 80 minutes and we paid for it."

Milan, who were missing three of their usual attackers from their starting line-up, including Mario Balotelli, came racing out of the blocks, putting pressure on Barca's backline and a defensive error led to Robinho's goal.

The Brazilian beat the away side's dithering defenders to a high bouncing ball, and after exchanging passes with revitalised-looking countryman Kaka, slid a simple finish past Victor Valdes.

"Kaka played extraordinarily well. He had to play almost as a full back in the second half," said Milan coach Massimiliano Allegri.

"To be a champions you can't only do it with your feet, but also with your head. Kaka showed that tonight once again."

The home side rarely looked troubled in the opening period, but found themselves back to square one only 14 minutes after scoring when they gave the ball away sloppily to Andres Iniesta.

The Spain midfielder picked up the otherwise excellent Cristian Zapata's misplaced pass and slipped in Messi on the right.

The Argentine cut inside and drilled low to level the score with his 63rd goal in 81 Champions League appearances just as he looked to have lost his footing.

Barca dominated the second half against a tired Milan, but despite a couple of good chances couldn't make the most of their possession and had to settle for a point.

"Milan were as we expected them to be, very tight. We couldn't find space but we tried to win the game and in the end a point isn't that bad for either side," Iniesta said.

Iniesta should have given his side the lead in the 55th minute when he collected Xavi's delicate pass and managed to break through Milan's stout backline, only to scuff his shot at full stretch and allow Marco Amelia to make a good save.

However, the best chance of the night fell to Robinho only two minutes beforehand, the Brazilian inexplicably letting the ball run past him after being brilliantly found by Sulley Muntari with only Valdes to beat and letting a famous win slip away.

Fit-again Fernando Torres sparkled on his 100th start for Chelsea, scoring twice to help the 2012 winners outclass Schalke 04 3-0 to go top of Champions League Group E on Tuesday.

Torres produced a flying header at the far post after Branislav Ivanovic had flicked on a Frank Lampard corner in the fifth minute.

The Spain striker, back in the starting lineup following a knee injury, struck again in the 69th minute when he raced clear to beat keeper Timo Hildebrand after earlier rattling the bar with a powerful header.

Eden Hazard made it 3-0 after running half the length of the field as Chelsea, who last played on German soil when they beat Bayern Munich in the 2012 final, took their points tally to six, level with Schalke but with a much better goal difference.

Basel drew 1-1 with bottom club Steaua Bucharest and are in third place on four points.

"I feel we are improving as a team and the last few games I have felt very sharp," Torres told Sky Sports television.

"We were lucky to score the first goal early. In the second half our individual quality made the difference.

"To have got six points away from home is very important," added Torres, referring to Chelsea's previous victory in Bucharest.

It was also coach Jose Mourinho's first away win against a German team, having lost all previous six visits in his career.

The Portuguese opted to start Torres up front instead of Cameroon international Samuel Eto'o who was on target in the Premier League last Saturday.

"I put faith in Fernando and he answered well. It's a good feeling to score winning goals in the Champions League," said Mourinho.

"That was an important victory for us. I told my players after the Basel defeat that the performance was garbage and we had to clean it up and we have done that with two consecutive victories away.

"We were under pressure after the first game but now, after this result, we are in a good position," added Mourinho.

Schalke, who had won their first two games, had the lion's share of possession but, hampered by a string of injuries that kept several players out including forward Klaas-Jan Huntelaar, they lacked bite up front.

"It was very unfortunate to concede first from a set-piece," said coach Jens Keller. "We had chances and we should have taken one of them because you don't get many against a quality side like Chelsea."

Chelsea started brightly and looked menacing in the opening 20 minutes although Schalke threatened to equalise after fighting back towards the end of the first half.

Petr Cech was called into action as he palmed a rocket shot by Kevin-Prince Boateng over the bar and the keeper then denied Roman Neustaedter, punching away his venemous close-range header.

Chelsea took control again at the start of the second half and it was no surprise when the dangerous Torres walked the ball around Hildebrand after an excellent breakaway raid by Hazard and Oscar.

The Spain striker also headed the ball against the underside of the bar after a clever free kick from Frank Lampard.

Hazard put the icing on the cake for Chelsea when he sprinted clear in the 87th minute and calmly slotted the ball past Hildebrand.

"After the opener Chelsea contributed little to the game but defended their lead. We weren't able to break through," said Schalke captain Benedikt Hoewedes.

"We risked more in the second half and it was then that Chelsea made some brutal breaks. They took crucial advantage from their counter attacks and made the most of our mistakes."

Robert Lewandowski's late volleyed winner threw Champions League Group F wide open as Borussia Dortmund heaped more German misery on Arsenal with a 2-1 victory at Emirates Stadium on Tuesday.

The match appeared to be petering out into a draw when the unmarked Pole was picked out at the far post by Kevin Grosskreutz in the 82nd minute and he sealed victory for last season's Champions League finalists.

Dortmund, whose coach Juergen Klopp had to watch the match from the stands following a touchline ban, had punished a slow start from the home side to take the lead through Henrikh Mkhitaryan after 16 minutes, but the hosts hit back before halftime through France striker Olivier Giroud.

Dortmund, Arsenal and Napoli, who won 2-1 at Olympique Marseille on Tuesday, have six points, with Marseille bottom with none. Borussia emulated Schalke and Bayern Munich who won at Arsenal in the Champions League last season.

Widely praised for their free-flowing football against NorwichCity at the weekend, Arsenal appeared to be basking in their own hype as Dortmund bossed the opening 20 minutes.

Marco Reus fired one dangerous effort wide after a swift break and with 16 minutes gone the visitors went ahead when Aaron Ramsey, who has hardly put a foot wrong this season, was robbed by Lewandowski on the edge of his own area.

Lewandowski played a quick pass to Armenian Mkhitaryan whose low shot nestled in the corner of Wojciech Szczesny's net.

Manager Arsene Wenger, celebrating his 64th birthday, looked apoplectic at the gift offered up by his Premier League leaders although Arsenal were nearly given an immediate reprieve when Mats Hummels felled Giroud inches outside the area and escaped with a booking. The resultant free-kick came to nothing.

Dortmund's yellow army of fans drowned out the home support for much of the half but Arsenal did finally stir into life with Jack Wilshere denied by Dortmund keeper Roman Weidenfelder after being sent clear by Tomas Rosicky, and Rosicky having a shot cleared off the line by Hummels.

The home pressure eventually told when Arsenal equalised four minutes before halftime. Weidenfelder and Hummels got in each other's way trying to deal with Bacary Sagna's cross and Giroud thumped the loose ball into an empty net for his seventh goal of the season.

Dortmund began the second half apparently intent on stifling Arsenal's momentum with a passage of "keep ball" in harmless areas of the pitch but it had the desired effect with Arsenal becalmed until the introduction of Santi Cazorla.

The Spaniard, on for the tiring Wilshere, injected energy into the hosts and curled a long-range shot against the angle of post and crossbar after being teed up Mesut Ozil.

A draw would have suited Arsenal and kept them in control of the group but Lewandowski provided a painful sting in the tail.

Brazil forward Hulk broke the hearts of his former club's supporters when he set up Aleksandr Kerzhakov's late winner for Zenit St Petersburg in a 1-0 Champions League victory at Porto on Tuesday.

The home team made it hard for themselves when Hector Herrera was sent off in the sixth minute. It was the quickest dismissal in the history of the competition for a player receiving two yellow cards.

Second-placed Zenit have four points from three games in Group G, five behind runaway leaders Atletico Madrid who beat Austria Vienna 3-0.

Porto are third with three points and Vienna have one.

All eyes at the Dragao stadium were on the burly Hulk who was back at the club where he spent four memorable years, and he received a hero's welcome.

Hulk had promised not to celebrate if Zenit scored and he kept his word after setting up substitute Kerzhakov for a fine header in the 86th minute.

"Everyone knows that part of my heart is with Porto. I have a lot of friends here and can only say thank you for such a warm welcome," Hulk told TVI television.

"When we receive Porto in Russia it is going to be hard. Perhaps even harder than it was today."

Midfielder Herrera won a rare starting place for Porto but he will want to forget his first Champions League start.

Celtic rode their luck to beat Ajax Amsterdam 2-1 with goals either side of halftime on Tuesday, their first points in Champions League Group H after two defeats.

The Dutch side, who failed to take a number of excellent chances, were incensed by a penalty awarded just before the interval when Anthony Stokes went down after a collision. James Forrest scored from the spot after a long delay.

Beram Kayal doubled the lead nine minutes into the second period with a deflected shot from outside the area.

Celtic's Nir Biton was sent off in the game's final stages for a late tackle on Thulani Serero and Ajax's Lasse Schoene reduced the deficit with a swerving effort in added time.

"That's a fantastic win for us, a monumental effort from those players tonight," said Celtic manager Neil Lennon.

Ajax's Frank de Boer felt the better side had ended up losing the game.

"I cannot be angry, we gave 120 percent, we created many chances. But in the end we had to score (from them)," the Dutch side's manager said.

Celtic have three points in Group H and Ajax one. The 1-1 draw between Milan and Barcelona leaves the Italians with five points and Barcelona top on seven.

Two superb goals earned Napoli a 2-1 win at Olympique Marseille on Tuesday that put the French team on the brink of elimination and the Italians back on course for a last-16 spot.

Jose Callejon and Duvan Zapata finished off excellent teamwork in style in the 42nd and 67th minutes to give Napoli six points from three matches, level with Arsenal and Borussia Dortmund. Marseille are bottom after three defeats.

Marseille reduced the arrears through Andre Ayew in the 86th minute but never came to terms with the astonishing pace of Belgium winger Dries Mertens.

"The coach told us that they had lost a lot of games lately so we had to put them under pressure early on," Mertens told Canal Plus. "Once we get the ball back, we are fast in front of goal, that's one of our qualities.

"Six points for everyone - too bad Dortmund won - but we now have two matches out of three at home." Napoli play host to Marseille in their next match.

Ayew said: "Once again we're disappointed. We just have to keep our mouths shut and get back to work. Now the most important thing is the league." Marseille have lost their last four games in all competitions.

Elie Baup's side came close early in the first half when Benoit Cheyrou's deflection off Jeremy Morel went just wide but that was about all the home side had to show for themselves.

Mertens, with his delicate turns and speed, proved a permanent threat to the Marseille defence.

In the 34th minute, at the end of a sharp counter-attack, Gonzalo Higuain missed a sitter, shooting wide despite being alone in front of goalkeeper Steve Mandanda.

Eight minutes later, midfielder Callejon opened the scoring following a superb defence-splitting pass from Higuain. The Spaniard chested the ball down and fired a half-volley past Mandanda as Napoli were rewarded for their domination.

Mertens flicked the ball into the path of the second-half substitute Zapata with a cunning back heel and the Colombian striker curled a shot into the top corner from 20 metres to put the visitors 2-0 up.

Striker Andre-Pierre Gignac was nowhere to be seen and was replaced in the 77th minute by Jordan Ayew. But it was the Ghana international's brother Andre who found the back of the net with a 20-metre half-volley to ease Marseille's pain.

One blot on Napoli's night was that seven of their fans were arrested by police for clashing with Marseille supporters. Several were slightly injured, police reported. 

An 88th-minute goal by substitute Leandro Tatu salvaged a 1-1 home draw for bottom club Steaua Bucharest in their Champions League Group E match against Basel at the National Arena on Tuesday.

Basel had taken the lead in the 48th minute when Chilean midfielder Marcelo Diaz gave keeper Ciprian Tatarusanu no chance with a delightful curling shot from outside the area after a blunder by Iasmin Latovlevici.

The Swiss club, who beat Chelsea in their opening game, are now third in the group with four points, two behind the Londoners and Schalke 04.

Steaua, winners of the European Cup in 1986, have one point.

The Romanians enjoyed a lot of possession but Basel created more scoring chances after finding holes in the home team's rearguard.

Basel almost took the lead in the 12th minute when centre back Ivan Ivanov's close-range shot was cleared off the line by defender Daniel Georgievski.

Tatarusanu then did well to parry an effort from Fabian Frei while Lukasz Szukala's brilliant block denied Mohamed Salah.

Behrang Safari also went close for the visitors when his shot hit the side-netting.

At the other end Cristian Tanase's shot from 25 metres was comfortably saved by Yann Sommer.

Valentin Stocker then hit the bar for Basel with a deflected shot five minutes before the break.

Steaua refused to give up and earned their reward when Brazilian striker Tatu, who came on as a second-half substitute, scored to delight the home fans.